Taming Cancer's Big 4 Killers

Lung Cancer | Breast Cancer | Prostate Cancer | Colon Cancer

Treatments for cancer can be almost as brutal as the disease itself. Nuking tumors with radiation and drugs or surgically excising them often works, but such tactics can leave patients—especially older individuals with fewer defenses—reeling from exhaustion, nausea, hair loss and other debilitating complications.

Now, kinder, gentler treatments are on their way. The newest strategy in the war on cancer is to understand the behavior of tumors and to pinpoint their weaknesses, enabling doctors to launch high-precision, therapeutic missiles that destroy only cancerous cells, not normal cells that help keep the body healthy.

"Traditional therapies have been more like nonspecific bombs: You throw them in, and hope you kill more bad cells than good ones," says Dennis Slamon, M.D., director of the Revlon/University of California-Los Angeles Women's Cancer Research Program. "The new therapy is directed at what's really broken. That's what's exciting about it."

Many recent developments in cancer research improve upon what for decades have been the mainstays of treatment: anti-cancer drugs (chemotherapy), radiation and surgery. Most new therapies will work in tandem with traditional treatments.

"Cancer patients should resist the temptation to look for a single drug to solve a complex disease," says Christopher Logothetis, M.D., professor and chairman of Genitourinary Medical Oncology at the University of Texas M. D. Anderson Cancer Center in Houston. "The greatest success will result when one of these new drugs is used in combination with established drugs or other novel ones being developed."

While scientists are experimenting with a host of potential methods—from laser surgery to gene therapy—to conquer cancer, most, for now, pin their hopes on drugs.

Some of the new medications (and other treatments) are now used mainly at major cancer centers, but their use is expected to spread as doctors become more familiar with them.

Other drugs are available only through clinical trials, as their dosages and results are reviewed. Most new therapies require approval by the Food and Drug Administration (FDA) before Medicare and private insurers make decisions about covering them.

What follows are some of latest, most promising treatments for the top four cancer killers: lung, breast, prostate and colon (colorectal) cancer. All are available or may be within five years.

First, a few important caveats: Some therapies are effective in treating just one or two types of cancer; others work on several types. Their use may depend on the cancer's specific cell type and how advanced the condition is.

LUNG CANCER

This cancer, leading to 154,900 deaths in the United States a year, kills more people than breast, prostate and colorectal cancer combined. About 169,400 new cases are diagnosed each year.

Finding successful treatment for lung tumors can be exceptionally difficult. "Lung cancer doesn't have just one cause or genetic defect to blame—even in the same tumor," says Roy S. Herbst, M.D., chief of thoracic medical oncology at Houston's Anderson Cancer Center. "No one agent by itself is going to do the job."

But doctors are testing several new therapies:

Directed radiation—In this procedure, called intensity modulated radiation therapy (IMRT), a CAT scan (a three-dimensional imaging device) and a computer are used to map organs and pinpoint radiation to the desired spot.

• pros: It's possible to give four to eight times more radiation with less chance of damaging healthy cells nearby.

• cons: Side effects include diarrhea, frequent urination and irritation of the colon or bladder.

• availability: Available now. Also used for prostate, gastrointestinal, head and neck cancers.

Inhaled cancer drugs—Thanks to inhalers much like those used for asthma, chemotherapy is delivered directly to the lungs.

• pros: Since the drug is inhaled, it stays mostly in the lung, rather than being diffused throughout the body, says Claudia Henschke, M.D., director of chest imaging at New York-Presbyterian Hospital.

• cons: The treatment's longer-term effectiveness is not yet known.

• availability: One to two years.

Smart bombs—Iressa and Tarceva are drugs known as monoclonal antibodies that seek out cancer cells and help block growth. "These drugs can also be used to aim destructive forces like radiation and chemotherapy directly at the cancer cells so there's less damage elsewhere," says Peter Schlegel, M.D., acting urologist-in-chief at New York-Presbyterian Hospital.

• pros: "There are many fewer side effects, making these drugs better for older patients," the Anderson Cancer Center's Herbst says. "Iressa is the best drug for lung cancer I've seen in my time as a clinician."

• cons: The drugs shrink only 10 percent of tumors and keep another 20 percent stable. They don't replace chemotherapy or radiation.

• availability: FDA's approval expected this summer for treating lung cancer and in two to three years for colon, breast, prostate and pancreatic cancer.

Lung Cancer | Breast Cancer | Prostate Cancer | Colon Cancer

BREAST CANCER

More than 203,500 women are diagnosed with breast cancer each year, and about 40,000 die, the American Cancer Society reports.

Some of the newest treatments against this lethal disease:

Growth stoppers—The drugs Herceptin and Tarceva block signals within cells that spur cancer growth.

• pros: Combined with chemotherapy, Herceptin is considered the best chance for survival in women with an overactive HER-2/neu gene. Tarceva stops cancer growth differently, so together the drugs may help more women than Herceptin alone, UCLA's Slamon says.

• cons: Herceptin works only for the 25 to 30 percent of breast cancers linked to the HER-2/neu gene.

• availability: The FDA approved Herceptin, which is covered by Medicare, in 1998. Tarceva may be available within two years.

Estrogen controls—Aromatase inhibitor drugs such as Arimidex and Femara starve cancers of an enzyme that converts a male hormone into the female hormone estrogen.

• pros: "Estrogen is involved in up to 80 percent of all breast cancers, so blocking its effects is vital to successful treatment," says Matthew Ellis, M.D., clinical director of Duke University's Breast Cancer Program in Durham, N.C.

• cons: When combined with Tamoxifen, a drug for estrogen-dependent cancers, Arimidex's benefits dropped. (Tamoxifen's effects on Femara have not been studied.)

• availability: Both drugs are now available.

Vaporizing cancer—Tumors can be frozen or vaporized with lasers or high-energy radio waves delivered via a needle inserted in a tiny cut, a fast procedure that requires just an overnight hospital stay.

• pros: "With just a probe into the breast, you can get rid of [small tumors]," says George Peters, M.D., executive director of the Center for Breast Care at the University of Texas Southwestern in Dallas.

• cons: Vaporizing only succeeds on single, small tumors less than 3/8 inch in diameter.

• availability: Already used for liver cancer; available within two to five years for breast, lung and possibly prostate cancer.

PROSTATE CANCER

Prostate cancer is the number one cancer in men, with 189,000 new cases and 30,200 deaths occurring annually.

Although prostate cancer death rates have dropped in recent years, better therapies are still needed. Chemotherapy has not been very effective, and prostate surgery can cause impotence or incontinence. Several improved treatments are in the pipeline. "Preliminary data for these new options is encouraging," urologist Schlegel says.

Radiation seeds—In this procedure, an ultrasound scan, which produces images from echoes of the body's sound waves, locates the tumor; a needle inserts up to 110 tiny radioactive beads into the prostate to shrink the tumor.

• pros: The process is so precise that side effects and harm to non-cancerous tissue are minimal. Coupled with surgery, radiation seeds (brachytherapy) have a 60 to 90 percent cure rate for prostate cancer, says Kenneth Koeneman, M.D., surgical urologic oncologist at the University of Texas Southwestern.

• cons: Radiation seeds only succeed if the cancer is confined to the prostate.

• availability: Available now; under study as a breast cancer treatment.

Surgery: no impotence—In this new technique, sural nerves are taken from the ankle area and implanted in the pelvis to replace the nerve responsible for potency that is removed in surgery.

• pros: "You can save a man's potency without sacrificing the extent of surgery," Logothetis of the Anderson Cancer Center says.

• cons: The operation takes longer, and the results, though promising, are considered unproven until clinical trials are completed.

• availability: Within two years.

COLON CANCER

The fourth most common cancer among both men and women leads to 148,300 diagnoses—and 56,600 deaths—each year, reports the American Cancer Society. New approaches to treatment include:

Radiation with surgery—In a procedure called intraoperative radiation therapy, radiation is applied during surgery as the surgeon exposes the cancer.

• pros: Radiation is delivered at a greater strength without damaging healthy tissue.

• cons: This treatment only works for those whose cancer is confined to one organ. "Unfortunately, if the cancer has spread to the liver or lungs, it's too late," says colorectal oncologist Michael O'Connell, M.D., of the Mayo Clinic in Rochester, Minn.

• availability: Now, at major cancer centers treating colon, brain, head and neck, gastrointestinal and lung cancers.

Starving tumors—Starvation is the idea behind Avastin, Endostatin and similar drugs that thwart the growth of blood vessels in tumors. "Without a blood supply delivering nutrients to cancer cells, tumors can't proliferate," says Robert Strieter, M.D., chief of pulmonary and critical care medicine at the University of California, Los Angeles.

• pros: These drugs have few side effects because they target only tumors and not healthy cells—and thus are better tolerated by older people.

• cons: The drugs are used with chemotherapy, an extremely effective but toxic mix, says Manuel Valdivieso, M.D., associate director for clinical investigations at the University of Texas Southwestern. A University of Toronto study also shows that tumors may adapt to the starvation forced by the drugs and thrive anyway.

• availability: Two to five years.